Commit 980d4f17 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Mauro Carvalho Chehab
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V4L/DVB (8751): vivi: Fix some issues at vivi register routine 



This patch fixes several small issues at vivi register routines:

1) minor and n_devs should be unsigned;
2) n_devs = 0 were not properly handled;
3) if n_devs specify a high number, the driver would just roll back and
won't register any device. The proper behaviour is to keep all succeded
devices registered;
4) both n_devs and minor were using 0 as permissions. Better to have
them with 0444.

With the current patch, if n_devs specify a very large value, it will
register all possible devices. For example, on a machine without any
other V4L drivers loaded, with this patch, we will have something like:

vivi: V4L2 device registered as /dev/video0
vivi: V4L2 device registered as /dev/video1
vivi: V4L2 device registered as /dev/video2
	...
vivi: V4L2 device registered as /dev/video31
video_register_device_index: get_index failed
Video Technology Magazine Virtual Video Capture Board ver 0.5.0 successfully loaded.

5) The number of allocated devices on success is now kept at n_devs:

$ cat /sys/module/vivi/parameters/n_devs
32

Thanks to Henne <henne@nachtwindheim.de> for pointing that there were
some issues at vivi.

Cc: Henne <henne@nachtwindheim.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent f3b9f50e

drivers/media/video/vivi.c

+36 −8
Original line number Diff line number Diff line
@@ -1104,19 +1104,29 @@ static struct video_device vivi_template = { 
	Initialization and module stuff

   ------------------------------------------------------------------*/



/* This routine allocates from 1 to n_devs virtual drivers.



   The real maximum number of virtual drivers will depend on how many drivers

   will succeed. This is limited to the maximum number of devices that

   videodev supports. Since there are 64 minors for video grabbers, this is

   currently the theoretical maximum limit. However, a further limit does

   exist at videodev that forbids any driver to register more than 32 video

   grabbers.

 */

static int __init vivi_init(void)

{

	int ret = -ENOMEM, i;

	struct vivi_dev *dev;

	struct video_device *vfd;



	if (n_devs <= 0)

		n_devs = 1;



	for (i = 0; i < n_devs; i++) {

		dev = kzalloc(sizeof(*dev), GFP_KERNEL);

		if (NULL == dev)

		if (!dev)

			break;



		list_add_tail(&dev->vivi_devlist, &vivi_devlist);



		/* init video dma queues */

		INIT_LIST_HEAD(&dev->vidq.active);

		init_waitqueue_head(&dev->vidq.wq);
@@ -1126,14 +1136,27 @@ static int __init vivi_init(void) 
		mutex_init(&dev->mutex);



		vfd = video_device_alloc();

		if (NULL == vfd)

		if (!vfd) {

			kfree(dev);

			break;

		}



		*vfd = vivi_template;



		ret = video_register_device(vfd, VFL_TYPE_GRABBER, video_nr);

		if (ret < 0)

		if (ret < 0) {

			video_device_release(vfd);

			kfree(dev);



			/* If some registers succeeded, keep driver */

			if (i)

				ret = 0;



			break;

		}



		/* Now that everything is fine, let's add it to device list */

		list_add_tail(&dev->vivi_devlist, &vivi_devlist);



		snprintf(vfd->name, sizeof(vfd->name), "%s (%i)",

			 vivi_template.name, vfd->minor);
@@ -1149,11 +1172,16 @@ static int __init vivi_init(void) 
	if (ret < 0) {

		vivi_release();

		printk(KERN_INFO "Error %d while loading vivi driver\n", ret);

	} else

	} else {

		printk(KERN_INFO "Video Technology Magazine Virtual Video "

			"Capture Board ver %u.%u.%u successfully loaded.\n",

			(VIVI_VERSION >> 16) & 0xFF, (VIVI_VERSION >> 8) & 0xFF,

			VIVI_VERSION & 0xFF);



		/* n_devs will reflect the actual number of allocated devices */

		n_devs = i;

	}



	return ret;

}
@@ -1169,10 +1197,10 @@ MODULE_DESCRIPTION("Video Technology Magazine Virtual Video Capture Board"); 
MODULE_AUTHOR("Mauro Carvalho Chehab, Ted Walther and John Sokol");

MODULE_LICENSE("Dual BSD/GPL");



module_param(video_nr, int, 0);

module_param(video_nr, uint, 0444);

MODULE_PARM_DESC(video_nr, "video iminor start number");



module_param(n_devs, int, 0);

module_param(n_devs, uint, 0444);

MODULE_PARM_DESC(n_devs, "number of video devices to create");



module_param_named(debug, vivi_template.debug, int, 0444);

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